Three teams of Royal Opera House staff are currently training hard in preparation for the Thunderwalk Challenge.

Thunderwalk, an endurance test that involves completing a 54-mile walking route in just 24 hours, takes place on Saturday 12 May in the Brecon Beacons National Park.

The route crosses the highest peaks in South Wales, including Pen Y Fan (886m), Corn Du (873m), Cribyn (795m) and Fan Y Big (719m), and promises to be a grueling test of stamina both mentally and physically.

Arnie Wilson and his team from the Wigs Department recently braved the elements to complete a training walk in the Brecons.

When we attempted to walk up Pen Y Fan the conditions were so bad we had to turn around. It was snowing with wind speeds over 30mph, and then hail that felt like bits of glass on the face...

Philippa Rooke, who recently spent a rainy weekend with her team in Buckinghamshire on a 27.5-mile training walk, said:

I knew when I signed up this would be a tough challenge, but I hadn't realised how difficult it would be. If you're training for a 54-mile walk you have to walk for at least six, then eight, then ten hours both days each weekend to get the stamina up and the legs fit. On top of that they recommend two-hour walks every other weekday! We must have walked nearly 1,000 miles between us in training. I can't wait to be able to go for a 5-mile walk with a pub lunch at the end!

The teams are aiming to raise over £5,000 for Together for Short Lives, formerly known as ACT and Children's Hospices UK. The charity provides care for young people not expected to live to reach adulthood, offering support to their families.

One pound pays for a child's oxygen mask, while £25 could pay for a child to have a music therapy session and £50 or an hour of nursing care for a child at home.